Trapania cf. brunnea in southern Queensland Australia
July 21, 2006
From: Gary Cobb
Hi Bill!
Please find attached photos of what can be either Trapania brunnea or T. benni. There were two animals found on an orange-pink sponge. Can you please tell me which one it is and whether it is a new record for southern Queensland.
Locality: Mooloolaba Sunshine Coast, 18 m, Queensland Australia, Pacific Ocean, 08 April 2006, Subtidal. Length: 7 mm. Photographer: Gary Cobb
There appears to be a flap in front of the gills, is this true?
Thanks
Gary Cobb
gary@nudibranch.com.au
Cobb, G., 2006 (Jul 21) Trapania cf. brunnea in southern Queensland Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16316Dear Gary,
This is the species which I discuss in Julie Marshall's message from Heron Island [#4120]. As I discuss there, it has features of the colour pattern of both the species you mention. It's most probably a form of T. brunnea but I think we need to look at its radular teeth to be sure. Neither of the named species have the white patch behind the gills extending back to the tip of the 'tail'.
I am pretty sure the apparent flap in front of the gills is just an extension of the colour pattern up onto the gills. These dorids do not have a branchial sac into which the gills can contract, so usually the gills arise directly from the skin of the mantle. Anything is possible, but I have looked at quite a few specimens of Trapania, alive and preserved, and have never found a flap. The presence of these animals on a sponge is not a random occurrence. Species of Trapania feed not on these sponges however, but on small stalked animals called Entoprocta [= kamptozoa, camptozoa] which are often found living on these sponges [see message #3767 ].
Best wishes,
Bill Rudman
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Trapania brunnea? from Heron Island
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